1. Technical Field
This disclosure relates generally to manufacturing a sandwich panel and, more particularly, to a forming a shaped sandwich panel with a die.
2. Background Information
A turbine engine may include a sandwich panel such as a high temperature, noise attenuation panel to reduce noise emitted during turbine engine operation and/or to reduce engine weight. The sandwich panel may be manufactured by bonding together layered metallic materials using a differential pressure bonding process, dead weight or tooling utilizing differing coefficients of expansion. The layered metallic materials may include a metal honeycomb core (e.g., open cell core) arranged between opposing metal skins (e.g., face sheets).
According to known bonding processes, a pressure differential may be applied across the layered metallic materials to simultaneously compress and bond the materials together at an elevated temperature. The layered metallic materials, for example, may be compressed between an inflatable pressure vessel and a support, and heated within a process chamber. The process chamber may be a vacuum furnace or an inert gas furnace. Bonding material is typically arranged between adjacent layers of the metallic materials, which material bonds the layers together; e.g., by liquid interface diffusion or brazing.
Subsequent to the bonding process, the sandwich panel may be shaped to have a simple or complex curved geometry; e.g., a cylindrical, conical, spherical or compound curved geometry. According to known techniques, the panel may be shaped by pressing the panel against a die with an inflatable pressure vessel, thereby causing the panel to assume the shape of the die. Such a formation technique can, however, crush or otherwise deform the honeycomb core portion of the panel, particularly when the adopted panel shape requires significant deformation.
There is a need in the art for an improved process for manufacturing a sandwich panel.